It relates in particular to a surface-mountable optoelectronic component, particularly leadframe-based, in which the semiconductor chip is disposed in a recess of a housing base body and there fastened. The housing base body is preferably prefabricated before the semiconductor chip is mounted in the recess.
Such semiconductor components are known for example from Siemens Components 29 (1991), Volume 4, pages 147-149. The encapsulant is conventionally for example an epoxy-resin-based potting material. However, such potting materials are often susceptible to UV radiation. They yellow relatively quickly under the effect of UV radiation and consequently reduce light output from the component.
To improve the UV resistance of radiation emitting optoelectronic semiconductor components, it has been proposed to use encapsulants based on or comprised of silicone resin. Such encapsulants do not yellow under the effect of short-wave radiation, or do so at a sufficiently slow rate.
A problem with encapsulants of this kind, however, is that the bond they form with the materials conventionally used for the housing base body (for example, a polyphthalamide-based thermoplastic material) is not sufficiently resistant to ageing, especially under UV exposure, as is the case for example with epoxy resin. As a result, when such an encapsulant is used in conventional housing designs, as described for example in Siemens Components 29 (1991), Volume 4, pages 147 to 149, there is an increased risk of delamination between the housing base body and the encapsulant, beginning at the upper margin of the recess and propagating on into it. In the worst case, this can lead to complete detachment of the chip encapsulant from the housing base body.